Views have been an important facility provided by database management systems (DBMSs) that allow users to access specific parts of a database. Over the years, views have remained useful in a wide range of emerging applications, such as data publishing or information dissemination, Extensible Markup Language (XML) or Resource Description Framework (RDF) query rewriting, query optimization and tracing facility in peer-to-peer (P2P) networks. It is evident that these applications not only query, but also update views as if they were the actual database. Updates on views are translated to updates on the source databases of the views, and the views and its source databases must keep consistent after updates.